Since the initial introduction of accumulator conveyors of the automatic type in which the operation of the conveyor to shift it between conveying and accumulation mode is automatically controlled by means of mechanisms responsive to the presence of articles on the conveyor, a wide variety of such mechanisms have been developed. When accumulation mechanisms were first introduced, the operating speeds of this type of conveyor was relatively slow compared to the speed now demanded of such conveyors. As the speed of operation of the conveyors has increased, the problem of reduction of noise resulting from the operating mechanisms of the conveyor has become increasingly serious. While various constructions have been developed to reduce the incident of noise, these have resulted in increased complexity and initial cost. These mechanisms have also not necessarily addressed the problem of an accumulator having the requisite sensitivity to be fully and dependably responsive to a wide range of article weights and sizes. It has been the experience of the conveyor industry that these varying demands have tended to impose conflicting requirements upon accumulator design. The invention provides substantial improvement in these various categories and an accumulator of a new and different construction.